Spatial Anchors won't stay after Recenter +Workaround

This matches a known initialization/order issue with tracking origin + anchors. I have seen it specially on LBE applications.

What’s happening:

• First scene loads without an active XR rig / OVRManager
• Anchors are created before tracking origin is fully stabilized
• First recenter redefines origin, so existing anchors appear to shift
• Sometimes even the initial origin is not in line with the headset origin so it needs recalibration

Your workaround is correct:

• Ensure OVRManager / XR rig exists in the first loaded scene
• Recalibrate the headset before anything!

Recommended pattern:

• Use a bootstrap scene that already contains OVRManager/XR Origin. AKA BootScene
• Or delay anchor creation until after tracking is fully initialized (e.g., a few frames or after first pose update)

Anchors created before XR is initialized will drift on first recenter, but if you initialize XR in scene 0 or delay anchor creation it will work correctly.